The present invention relates to a voice over Internet protocol (VoIP) system and more particularly to an improved VoIP system serving a dedicated distributed group of teleagents.
Many companies, governmental agencies and other organizations (collectively “enterprises”) are interested in having employees work from home rather than commute to an office each day. Indeed, many enterprises will hire hundreds or thousands of customer service representatives during peak months to handle an expected increase in call volume. For example, a catalog company may hire customer service agents during the holiday shopping season to handle the large volume of telephone sales orders or an insurance company may add agents to process insurance claims after a natural disaster. Clearly, the cost to provide an office for each of these agents would be cost prohibitive but such cost can be avoided if the agents are able to tele-commute. Indeed, as the cost of maintaining office space escalates, enterprises find that tele-commuting, that is, working from a home office rather than commuting to the enterprise's office each day, can generate substantial savings.
With the increased availability of high speed Internet and voice over Internet protocol (VoIP) technology, agents can both access the enterprise's computer systems and communication network as if they were working from the enterprise's office. A home office arrangement provides great benefit for both the enterprise and the agent because the enterprise saves the money it would normally spend on leasing office space and the agent saves the time normally spent commuting. Agents, or employees, working from their home or where ever they may find a broadband connection to the Internet are often referred to as ‘teleagents’. Teleagents may include call center agents who answer telephone inquiries for their employer, employees who, while working from home or on the road, support sales, marketing, engineering or manufacturing activities for their employer or business and government employees who are widely deployed in order to provide the ability to respond in the event of a disaster at corporate headquarters.
Many companies supply VoIP technology that can be used by the teleagent. For example, Cisco Systems, Inc. of San Jose, Calif., the assignee of the present application, currently markets voice and video enabled VPN solutions that integrate cost-effective, secure connectivity provided by site-to-site IPSec VPNs for delivering converged voice, video, and data IP networks. These solutions are marketed by Cisco under the name of V3PN and are typically a site-to-site VPN deployment using T1 lines and the Internet so voice quality is similar to that of a toll call. When design guidelines for IPSec over ADSL are followed, a caller cannot hear a difference in voice quality when the IP telephone is connected from the employee home over a broadband connection. IPsec refers to an IP security protocol developed by the Internet Engineering Task Force (IETF), the main standards organization for the Internet, to support secure exchange of packets at the IP layer. IPsec has been deployed widely to implement Virtual Private Networks (VPNs). ADSL refers to Asymmetric Digital Subscriber Lines that are used to deliver high-rate digital data over existing ordinary phone-lines. ADSL facilitates the simultaneous use of normal telephone services and high speed data transmission rates of about 1.5 to 9 megabits per second (Mbps) when receiving data (known as the downstream rate) and from 16 to 640 kilobits per second (Kbps) when sending data (known as the upstream rate).
While the Internet is capable of providing consistent and reliable transport of encrypted voice approaching toll quality, voice quality will vary depending on the Internet Service Provider (ISP) and various network parameters such as loading, network equipment type and age, available bandwidth, the type of equipment used by the teleagent and the like.
Since one purpose of allowing agents to tele-commute is to reduce costs, enterprises need a method to ensure toll quality voice service to teleagents who may be deployed anywhere in the country or even in other countries. Further complicating the effort to ensure toll quality voice service, most of the teleagents have inexpensive basic residential broadband service with limited bandwidth. Indeed, the available bandwidth provides the minimum bandwidth needed to support VoIP and it is not uncommon for such bandwidth to vary over time. Thus, one major obstacle to supporting teleagents is the difficulty in managing the communication network between a large number of teleagents, deployed over a large geographic area and enterprise's computer infrastructure so that customers and suppliers experience a VoIP telephone call that has comparable voice quality to that of a toll call placed over the switched telephone network. What is needed is a method for determining when a teleagent does not have a broadband connection sufficient to meet the voice quality needs of an enterprise.
Another complication facing a network administrator tasked to manage a large deployment of teleagents, arises because not all broadband Internet Service Providers (ISPs) have adequate service level agreements necessary to support both voice and data transmission over a high-speed ADSL connection. Further, not all ISPs have the necessary degree of reliability and availability comparable to that provided by the Internet backbone providers. Indeed, the quality of the connection may vary with a single ISP over time. All of these parameters will affect voice quality and are often times of a transient nature. What is needed is a method for quantifying both subjective and objective determinations of network conditions to determine if voice quality will meet the needs of an enterprise.
Unfortunately, for the network administrator tasked to manage the deployment of teleagents, there is yet another complication in managing deployed teleagents. This complication arises because of the widely varying differences in network quality inside the teleagent's home. Factors such as the age and the type of the cabling in the teleagent's home, their distance from the ISP's demark point, the loading on the network due to use of the ADSL connection by other family members or whether DSL filters are installed and working properly can all negatively impact the quality of the VoIP call. These environmental factors are outside the control the ISP so there must be some mechanism to monitor the call quality for each teleagent depending on their location and identify the source of negative factors that affect voice quality.
It is widely known that there are existing tools that can be used to monitor a communication network. For example, Cisco markets a tool, known as ‘Cisco's NetFlow Services’, that captures traffic statistics by IP address, protocol, port, and type of service (ToS). It identifies and reports on network flows of packets between a given source and destination. Unfortunately, this tool is not dedicated to providing toll quality voice for teleagents or reporting its information that is readily useable by a network administrator responsible for managing the deployment of teleagents.
Cisco also markets a network-based application recognition (NBAR) classification engine that can recognize a wide variety of applications such as, by way of example, a voice call. Once the application is recognized, NBAR works with quality-of-service (QoS) features to guarantee bandwidth to critical applications, limit bandwidth to other applications or drop selective packets to avoid congestion on the network. Unfortunately, this tool is not dedicated to providing toll quality voice for teleagents or reporting its information that is readily useable by a network administrator responsible for managing the deployment of teleagents.
Yet another Cisco product is commercially available and marketed as Service Assurance Agent (SAA). SAA is an application-aware synthetic operation agent that generates data requesting packets at a specified router. The packets are then transferred back to the initiating router for analysis and reporting. SAA allows routers to measure and report network application round trip times. SAA uses simulated application traffic to routers configured as responders. By taking iterative round trip measurements, it is possible to calculate a variance, which is useful in determining jitter for voice traffic. SAA reports both positive and negative jitter.
Yet another tool marketed by Cisco is the Internetwork Performance Monitor (IPM). The IPM is a network response time and availability troubleshooting application that uses SAA probes enable the network administrator to proactively troubleshoot network-wide performance, diagnose congestion and latency problems utilizing real time and historical statistics. Unfortunately, this tool is not dedicated to providing toll quality voice for teleagents or reporting its information that is readily useable by a network administrator responsible for managing the deployment of teleagents.
While the network measurement and management tools are commercially available, the results generated by these tools are difficult to interpret in a VoIP system. Indeed, while data about certain network parameters may be available, it is not readily possible to correlate measured data to actual voice quality problems. Thus, in addition to the objective measurements provided by network tools, there also needs to be a subjective means for identifying poor voice quality and correlating such objective and subjective information in a manner that is useable by a network administrator in troubleshooting poor voice quality. Accordingly, a simple tool that can monitor the communication network, identify network problems, both objective and subjective, and initiate a method for the network administrator to initiate a corrective action to resolve the problems of poor voice quality would greatly assist a network administrator who was responsible for managing a network of deployed teleagents.